Thanks for your reply taazz.
I am starting with a plain bitmap (a geographical map). I then add lines, circles etc to build up specific groupings. I then combine them together and save as bmp or png. I could put the extra graphics directly on the bitmap, but if there are any changes, then I would have to delete the whole image and start again.
I have tried using bmp and png (transparency works in Delphi) with TImage, TLazIntfImage, TLazCanvas, TRawImage etc but none seem to support transparency on Android.
I am using Lazarus 1.1, FPC 2.7.1 SVN 41139, on Windows 7 Ultimate + Service Pack 1. The android device is Huawei Ascend Mate, and previously HTC.
Regards